Antifouling Polymeric Coating Compositions

ABSTRACT

Provided herein are compositions comprising: (a) a polymeric catechol binder, such as: polymeric dopamine, polymeric norepinephrine, polymeric epinephrine; polymeric pyrogallol, polymeric tannic acid, polymeric hydroxyhydroquinone, polymeric catechin, polymeric epigallocatechin etc.; and (b) a hydrophilic polymer, methods for using the compositions to coat a substrate, and methods for making the compositions. In particular, the substrate may form part of an apparatus on which it would be beneficial to limit biofouling and/or protein binding.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/166,255 filed on 26 May 2015, entitled “ONE-STEPAPPROACH TO UNIVERSAL ANTIFOULING COATINGS”.

TECHNICAL FIELD

The present invention relates to catechol polymer and catecholderivative polymer coating field. In particular, the invention relatesto catechol polymers or catechol derivative polymers in combination withcertain hydrophilic polymers to form compositions, to provide methodsfor making the compositions and to provide uses for the compositions.

BACKGROUND

In an aging society, medical devices are increasingly used to improve apatients' quality of life and to extend their life expectancy. Forexample, intravascular catheters are used to deliver fluids or drugsinto bloodstream, and urinary catheters are used to drain waste fluidsfrom the body. In spite of their extensive use, medical devices, such ascatheters, are associated with two major challenges: thrombus formationand biofouling or biofilm formation. When such a medical device isinserted into the body of a living organism, a cascade of events isinitiated, including protein adsorption, platelet adhesion andactivation, complement proteins binding and activation, cellularactivation, and cellular attachment on the device surface. These eventsmay initiate host response to the device including the initiation of thecoagulation cascade and an inflammatory response leading the formationthrombus and cell attachment on the device surface. In addition, deviceshaving a hydrophobic surface may provide an initial attachment site formicroorganisms, which may attach and grow on the device surface and formmicrobial biofilms. When such microbial growth and/or thrombus formationoccurs in an already immune-compromised patient, this may lead toelongated treatment times or even death.

Although hydrophilic polymer coatings have shown significant advantagesas antifouling coatings, it has proven challenging to translate thetechniques that have been developed on model surfaces to real worldbiomedical plastics. For example, many commercially available biomedicaldevices consist of undefined polymeric components, and it is challengingto apply one coating method to all the polymeric devices. Many of thecurrent coating technologies do not meet all the criteria needed for thetranslation to medical devices, including the prevention of thrombus andbiofilm formation, adaptation to multiple materials and surfaces, easyapplication of the coating to devices of various sizes and shapes andmaterials, stability of the coating, and economic feasibility.

Mussel-inspired catechol surface chemistry provide numerous strategiesthat have been used to develop and generate bio-inert coatings on devicesurfaces. Dopamine and its derivatives mimic the composition of musselfoot proteins, forming surface-adherent coatings on a wide array ofmaterials. One strategy endowed different substrates with antifoulingfunctions via post-modification of polydopamine (PDA) by attaching areactive PDA layer on the surface and then reacting the functionalizedhydrophilic polymers with the PDA layer via the thiol or amino groups onthe hydrophilic polymers. Using this method, PDA coatings have beenpost-modified with functionalized polyethylene glycol, hyperbranchedpolyglycerol, zwitterionic polymers, and zwitterionic peptide, leadingto a significant reduction of protein adsorption and cell adhesion.However, one limitation of these types of coatings is that they are verythin and lack long-term antifouling properties. Another strategyutilizes the anchoring and crosslinking properties of the catecholmodality to develop antifouling coatings. In this case, polymer-catecholconjugates were utilized for the generation of an antifouling layer on asurface. Various non-fouling polymers were conjugated with catecholgroups, and these conjugates were successful for developing coatingsurfaces (SUNDARAM, Harihara S. et al. Advanced Materials Interfaces(2014) 1: 1400071). However, the majority of these systems were onlyable to introduce a low density of catechol groups in the structure dueto solubility issues. Such conjugates showed poor coating ability onpolymeric materials due to lack of intermolecular crosslinking. Hence,it is challenging to coat hydrophilic polymers onto different surfaceswith optimized thickness via a simple dipping process.

The exact mechanism of dopamine polymerization has not yet been clearlydemonstrated. Some groups have suggested that PDA results from covalentbonding (HONG, Seonki et al. Advanced Functional Materials (2012) 22:4711-4717), while others suggest a supramolecular aggregate of monomerthat are held together through a combination of charge transfer,π-stacking and hydrogen bonding interactions [DREYER, Daniel R. et al.Langmuir (2012) 28:6428-6435].

Additionally, U.S. Pat. No. 8,541,060 discloses the use of asurface-modifying agent (SMA), such as dopamine and other catechols, toform a polymeric coat on a substrate, WO2011/005258 describes thecombination of PDA and amine functionalized PEG and U.S. Pat. No.8,962,772 discloses a catechol layer covalently linked to aantimicrobial cationic polycarbonate. Some groups have successfullyincorporated low molecular weight polyvinyl alcohol [ZHANG, Yan et al.Langmuir (2012) 28:17585-17592], biomacomolecules including Dextran[LIU, Yunxiao et al. Langmuir (2014) 30:3118-3126] and, and heparinhyaluronic acid (HUANG, Renliang et al. Langmuir (2015) 31: 12061-12070)onto the surface during dopamine polymerization via supramolecularinteraction. However, the obtained surface coatings exhibited limitedantifouling performance.

SUMMARY

The present invention is based, in part, on the surprising discoverythat the combination of a polymeric binder as described herein with ahigh molecular weight hydrophilic polymer as described herein produced acomposition useful for coating a substrate. Furthermore, thosesubstrates, when coated showed further useful properties. In someembodiments, the combination of a polymeric binder as described hereinwith a high molecular weight hydrophilic polymer as described hereinexhibited useful properties that make them especially useful for coatingsubstrates, whereby they allow for a single step application to asubstrate. In other embodiments, the combination of a polymeric binderas described herein with a high molecular weight hydrophilic polymer asdescribed herein provided a substrate coating that became smoother asthe molecular weight of the hydrophilic polymer increased. Similarly, itwas surprisingly discovered that when a composition comprising apolymeric binder as described herein was combined with a hydrophilicpolymer as described herein, the substrate coatings produced in someembodiments coated a substrate more uniformly as the molecular weight ofthe hydrophilic polymer increased. In addition, in the compositionstested it was surprisingly discovered that as the molecular weight ofthe hydrophilic polymer increased the antifouling properties alsoimproved. Similarly, in some of the compositions tested it wassurprisingly discovered that as the molecular weight of the hydrophilicpolymer increased the antithrombotic properties also improved. In someof the compositions tested, it was surprisingly discovered that as themolecular weight of the hydrophilic polymer increased the uniformity ofthe coating on the substrate improved.

In accordance with one embodiment, there is provided a composition, thecomposition, the composition comprising: (a) a polymeric binder, whereina monomer of the polymeric binder may have the following structure:

wherein, D¹ may be selected from H, OH,

D² may be selected from H, OH,

D³ may be selected from H, OH,

D⁴ may be selected from H, OH,

wherein E¹ may be H or

wherein E² may be H or

and (b) a hydrophilic polymer, wherein the hydrophilic polymer iscomprised of monomer units having the following structure:

II wherein, G may be H or CH₃; R may be selected from

and m may be an integer between 400 and 5,000,000.

In accordance with another embodiment, there is provided a coatedsubstrate, the coated substrate comprising: (a) a substrate; (b) apolymeric binder bound to the substrate, wherein a monomer of thepolymeric binder may have the following structure:

wherein, D¹ may be selected from H, OH,

D² may be selected from H, OH,

D³ may be selected from H, OH,

D4 may be selected from H, OH,

wherein E¹ may be H or

wherein E² may be H or

and (c) a hydrophilic polymer bound to the polymeric binder, wherein thehydrophilic polymer may be comprised of monomer units having thefollowing structure:

wherein, G may be H or CH₃; R may be selected from

and m may be an integer between 400 and 5,000,000.

In accordance with another embodiment, there is provided a method ofcoating a substrate, wherein the substrate is immersed in a solutioncomprising the composition described herein.

In accordance with another embodiment, there is provided a method ofcoating a substrate, wherein the substrate is sprayed with a solutioncomprising the composition described herein.

In accordance with another embodiment, there is provided a use of acomposition described herein for coating a substrate.

In accordance with another embodiment, there is provided a coatedsubstrate described herein for preventing biofouling of the substrate.

In accordance with another embodiment, there is provided a coated asubstrate as described herein for use in preventing adhesion to thesubstrate.

In accordance with another embodiment, there is provided a coated asubstrate as described herein for use in preventing thrombus formation.

D¹ may be selected from H, OH,

D¹ may be selected from H, OH,

D¹ may be selected from H, OH,

D¹ may be selected from H, OH,

D¹ may be selected from H and OH.D² may be selected from H, OH,

D² may be selected from H, OH,

D² may be selected from H, OH,

D² may be selected from H, OH,

D² may be selected from H, OH,

D² may be selected from H, OH,

D² may be selected from H,

D² may be selected from OH,

D² may be selected from

D² may be selected from H, OH, and

D³ may be selected from H, OH,

D³ may be selected from H, OH,

D³ may be selected from H, OH,

D³ may be selected from H, OH,

D³ may be selected from H, OH,

D³ may be selected from H, OH,

D³ may be selected from H,

D³ may be selected from OH,

D³ may be selected from

D³ may be selected from H, OH, and

D⁴ may be selected from H, OH,

D⁴ may be selected from H, OH,

D⁴ may be selected from H, OH,

D⁴ may be selected from H, OH,

D⁴ may be selected from H and OH.

E¹ may be H or

E¹ may be H. E¹ may be

E² may be H or

E² may be H. E² may be

G may be H or CH₃. G may be CH₃. G may be H. R may be selected from

R may be selected from

R may be selected from

R may be selected from

R may be selected from

R may be selected from

R may be selected from

R may be

R may be

m may be an integer between 400 and 5,000,000. m may be an integerbetween 200 and 5,000,000. m may be an integer between 300 and5,000,000. m may be an integer between 400 and 6,000,000. m may be aninteger between 400 and 7,000,000. m may be an integer between 200 and10,000,000. m may be an integer between 400 and 12,000,000. m may be aninteger between 400 and 4,000,000. m may be an integer between 400 and3,000,000. m may be an integer between 400 and 2,000,000. m may be aninteger between 400 and 1,000,000. m may be an integer between 400 and500,000.

The composition may further include a buffer. The composition mayfurther include an aqueous solution. The aqueous solution may be withouta salt. The aqueous solution may be with a salt. The composition mayfurther include a water soluble organic solvent. The water solubleorganic solvent may be selected from one or more of: alcohol, DMF, DMSO,acetonitrile and acetone. The composition may further include water. Thebuffer may have a pH of between 7 and 12. The buffer may have a pH ofbetween 7 and 11. The buffer may have a pH of between 7 and 10. Thebuffer may have a pH of between 7 and 9. The buffer may have a pH ofbetween 7 and 8. The buffer may have a pH of between 7.3 and 10. Thebuffer may have a pH of between 7.4 and 10. The buffer may have a pH ofbetween 7.5 and 10. The buffer may have a pH of between 7.6 and 10. Thebuffer may have a pH of between 7.7 and 10. The buffer may have a pH ofbetween 8 and 10. The buffer may have a pH of between 8 and 11. Thebuffer may have a pH of between 8 and 12. The buffer may be without asalt. The buffer may include a salt. The ratio of the polymeric binderto hydrophilic polymer may be between 100:1 and 1:100. The ratio of thepolymeric binder to hydrophilic polymer may be between 1:1 and 1:30. Theratio of the polymeric binder to hydrophilic polymer may be between 1:5and 1:15. The ratio of the polymeric binder to hydrophilic polymer maybe between 1:2 and 1:10. The ratio of the polymeric binder tohydrophilic polymer may be between 1:1 and 1:10. The ratio of thepolymeric binder to hydrophilic polymer may be between 1:3 and 1:10. Theratio of the polymeric binder to hydrophilic polymer may be between 1:4and 1:10. The ratio of the polymeric binder to hydrophilic polymer maybe between 1:1 and 1:15. The ratio of the polymeric binder tohydrophilic polymer may be between 1:2 and 1:15. The ratio of thepolymeric binder to hydrophilic polymer may be between 1:3 and 1:15. Theratio of the polymeric binder to hydrophilic polymer may be between 1:4and 1:15. The ratio of the polymeric binder to hydrophilic polymer maybe between 1:5 and 1:12.

The hydrophilic polymer may have a number average molecular weight(M_(n)) of at least 100 kDa. The hydrophilic polymer may have a numberaverage molecular weight (M_(n)) of at least 150 kDa. The hydrophilicpolymer may have a number average molecular weight (M_(n)) of at least200 kDa. The hydrophilic polymer may have a number average molecularweight (M_(n)) of at least 250 kDa. The hydrophilic polymer may have anumber average molecular weight (M_(n)) of at least 213 kDa. Thehydrophilic polymer may have a number average molecular weight (M_(a))of at least 300 kDa. The hydrophilic polymer may have a number averagemolecular weight (M_(n)) of at least 350 kDa. The hydrophilic polymermay have a number average molecular weight (M_(n)) of at least 400 kDa.The hydrophilic polymer may have a number average molecular weight(M_(n)) of at least 450 kDa. The hydrophilic polymer may have a numberaverage molecular weight (M_(n)) of at least 500 kDa. The hydrophilicpolymer may have a number average molecular weight (M_(n)) of at least600 kDa. The hydrophilic polymer may have a number average molecularweight (M_(n)) of at least 700 kDa. The hydrophilic polymer may have anumber average molecular weight (M_(n)) of at least 795 kDa. Thehydrophilic polymer may have a number average molecular weight (M_(n))of at least 800 kDa. The hydrophilic polymer may have a number averagemolecular weight (M_(n)) of at least 900 kDa. The hydrophilic polymermay have a number average molecular weight (M_(n)) of at least 996 kDa.

The the polymeric binder may be selected from one or more of: polymericdopamine (PDA); polymeric norepinephrine (PNE); polymeric epinephrine(PEPI); polymeric pyrogallol (PPG); polymeric tannic acid (PTA);polymeric hydroxyhydroquinone (PHHQ); polymeric catechin; and polymericepigallocatechin. The polymeric binder may be selected from one or moreof: polymeric dopamine (PDA); polymeric norepinephrine (PNE); polymericepinephrine (PEPI); polymeric pyrogallol (PPG); and polymeric tannicacid (PTA). The polymeric binder may be selected from one or more of:polymeric dopamine (PDA); polymeric norepinephrine (PNE); polymericepinephrine (PEPI); and polymeric pyrogallol (PPG). The polymeric bindermay be selected from one or more of: polymeric dopamine (PDA); polymericnorepinephrine (PNE); polymeric pyrogallol (PPG); and polymeric tannicacid (PTA). The polymeric binder may be selected from one or more of:polymeric dopamine (PDA); polymeric epinephrine (PEPI) and polymericnorepinephrine (PNE). The polymeric binder may be polymeric dopamine(PDA).

The hydrophilic polymer may be selected from one or more of:poly(acrylamide) (PAM); poly(N,N-dimethyl acrylamide) (PDMA);poly(N-hydroxymethyl acrylamide) (PHMA); poly(N-hydroxyethyl acrylamide)(PHEA); poly{N-[tris(hydroxymethyl) methyl]acrylamide} (PTHMAM);poly(N-(2-hydroxypropyl)methacrylamide) (PHPMA);poly(N-(3-(methacryloylamino)propyl)-N,N-dimethyl-N-(3-sulfopropyl)ammonium hydroxide) (PMPDSAH); and poly(2-methacryloyloxyethylphosphorylcholine) (PMPC). The hydrophilic polymer may be selected fromone or more of: PAM; PDMA; PHMA; PHEA; and PHPMA. The hydrophilicpolymer may be selected from one or more of: PAM; and PDMA. Thehydrophilic polymer may be selected from one or more of: PDMA; and PHMA.The hydrophilic polymer may be selected from one or more of: PDMA; andPHEA. The hydrophilic polymer may be selected from one or more of: PDMA;and PHPMA. The hydrophilic polymer may be selected from one or more of:PAM; PDMA; and PHMA. The hydrophilic polymer may be selected from one ormore of: PAM; PDMA; and PHEA. The hydrophilic polymer may be selectedfrom one or more of: PAM; PDMA; and PHPMA. The hydrophilic polymer maybe selected from one or more of: PDMA; PHMA; and PHEA. The hydrophilicpolymer may be selected from one or more of: PDMA; PHMA; and PHPMA. Thehydrophilic polymer may be selected from one or more of: PAM; PDMA;PHMA; and PHEA. The hydrophilic polymer may be selected from one or moreof: PAM; PDMA; PHMA; and PHPMA. The hydrophilic polymer may be selectedfrom one or more of: PAM; PDMA; PHEA; and PHPMA. The hydrophilic polymermay be selected from one or more of: PDMA; PHMA; PHEA; and PHPMA. Thehydrophilic polymer may be PDMA.

The substrate may be a plastic, a metal, a ceramic, a carbon basedmaterial, a metal oxide, a hydrogels, a biological tissue, a wood or acement. The substrate may be poly(propylene) (PP); poly(urethane) (PU);poly(ethylene) (PE); unplasticized polyvinyl chloride (uPVC);plasticized polyvinyl chloride (pPVC); poly(imide) (PI); ethylene vinylacetate (EVA); poly(tetrafluoroethylene) (PTFE); titanium dioxide(TiO₂), or silicon dioxide (SiO₂). The substrate may be PP, PU, PE,uPVC, pPVC, PI, EVA, or PTFE. The substrate may be TiO₂ or SiO₂. Thesubstrate may form part of an apparatus. The apparatus may be selectedfrom: a urinary device; a dental fixture; an artificial joint; avascular device; a storage device; a microfluidic device; a filtrationmembrane; a feed tube; or a diagnostic device. The vascular device may acatheter, a lead, or a stent. The urinary device maybe a urine storagedevice, catheter, or a stent. The filtration membrane may be a bloodfiltration membrane, a water purification membrane, or an airpurification membrane.

The method may further comprise drying the substrate. The method mayfurther comprise applying a further coat of the solution following thedrying of the substrate. The method may further comprise a second dryingof the substrate. The method may further comprise one or morerepetitions of the applying a further coat of the solution followed byone or more subsequent drying steps. The method may further comprisemechanical agitation following immersion in the solution. The method mayfurther comprise the application of a primer, prior to immersion in orspraying of a solution comprising a composition described herein. Thedrying may be in flow of argon gas or a flow of nitrogen gas.

The composition described herein may be for use as an anti-foulingagent. The composition described herein may be for use as ananti-adhesion agent. The coated substrate described herein may be forreducing biofouling. The coated substrate described herein may be forreducing adhesion. The coated substrate described herein may be forreducing thrombus formation.

The coating may be of uniform thickness. The coating may be applied in 2coats. The coating may be applied in 3 coats. The coating may be appliedin 4 coats. The coating may be applied in 5 coats. The coating may beapplied in 6 coats. The coating may be applied in 7 coats. The coatingmay be applied in 8 coats. The coating may be applied in 9 coats. Thecoating may be applied in 10 coats. The coating may be applied in 1coat.

The methods described herein may be for preventing thrombus formation;biofouling; biofilm formation; protein adsorption; protein binding; celladhesion; platelet adhesion; microorganism adhesion; and microorganismadhesion and growth. The microorganism may be bacteria. The bacteria maybe Gram-positive or Gram-negative bacteria. The gram-positive bacteriamay be Staphyloccous aureus (S. aureus). The gram-negative bacteria maybe Escherichia coli (E. coli).

The coating solution may comprise a coating comprising PDA andhydrophilic polymer with a molecular weight of 300 kDa and higher. Thecoating solution may comprise a solution comprising PDA and hydrophilicpolymer with a molecular weight of 300 kDa and higher. The coatingsolution may comprise a PDA and a hydrophilic polymer with a molecularweight of 300 kDa and higher.

The hydrophilic polymer may be PAM, PDMA, PHMA, PHEA, PTHMAM, PMA,PHPMA, PMPDSAH, PMPC, PVP, PEO, HPG, or Dextran. The hydrophilic polymermay be PDMA, PHPMA, PAM, or PHEA. The hydrophilic polymer may be PDMA.In a further embodiment the formed polymeric particles may be uniform.In a further embodiment the polymeric particles of the coating may beuniform.

The method of coating a surface, may include providing a solutioncomprising PDA and hydrophilic polymer and contacting said solution withthe surface of a substrate. Wherein the method is substrate independent,and wherein the method of contacting the solution and surface of thesubstrate may be as a dip-coating. Wherein the substrate may be aplastic, a metal, a ceramic, a carbon based material, a metal oxide, ahydrogels, a biological tissue, a wood or a cement.

In a further embodiment the present invention provides a method ofcoating a surface, wherein the method comprises providing a solutioncomprising PDA and hydrophilic polymer of molecular weight above 300 KDaand applying said coating to a substrate.

The method may be substrate independent, and wherein the method ofapplication may be as a dip-coating. The substrate may be plastic,metal, or metal oxide. The substrate may be one or more of PP, PU, PE,uPVC, pPVC, PI, EVA, Teflon, titanium dioxide (TiO₂), or silicon dioxide(SiO₂). The substrate may be PP, PU, PE, uPVC, pPVC, PI, EVA, or Teflon.The substrate may be TiO₂ or SiO₂.

The coating may be of high lubricity. The coating may prevent biofilmformation. The coating may be for the prevention of protein adsorption,protein binding, cell adhesion, platelet adhesion, or microorganismadhesion. The coating may prevent microorganism adhesion and growth. Thesubstrate may be a medical implant or device.

The coating may be applied to urinary implants and devices, dentalfixtures, artificial joints, vascular stents, or other type of vascularimplant and devices, as well as blood filtration systems, blood storagedevices, microfluidic devices and diagnostic devices. The coatingdescribed herein may also be used ex vivo.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a schematic illustration of deposition of high molecularweight hydrophilic polymers and dopamine on a substrate in an alkalinesolution.

FIG. 1B shows the chemical structures of the monomer units that may upsome of polymers tested herein.

FIG. 2A shows surface characterization (binding energy (ev)) of PDA,PDA/PDMA-43K, PDA/PDMA-213K and, PDA/PDMA-795K coated silicon wafers byXPS spectra.

FIG. 2B shows water contact angles for polypropylene (PP) substrate, PPcoated in PDA, PP coated in PDA/PDMA-43K, PP coated in PDA/PDMA-146K, PPcoated in PDA/PDMA-213K, PP coated in PDA/PDMA-412K, PP coated inPDA/PDMA-795K and PP coated in PDA/PDMA-996K.

FIG. 2C shows adsorption of bovine serum albumin (BSA) and Fibrinogen(Fib) onto the different molecular weight PDMAs (i.e. PP coated inPDA/PDMA-43K, PP coated in PDA/PDMA-146K, PP coated in PDA/PDMA-213K, PPcoated in PDA/PDMA-412K, PP coated in PDA/PDMA-795K and PP coated inPDA/PDMA-996K) deposited PP films as compared to uncoated PP and PDAonly coated PP.

FIG. 2D shows normalized bacterial density of adhered S. aureus onuncoated PP and PDA only coated PP, as compared to PP coated inPDA/PDMA-43K, PP coated in PDA/PDMA-146K, PP coated in PDA/PDMA-213K, PPcoated in PDA/PDMA-412K, PP coated in PDA/PDMA-795K and PP coated inPDA/PDMA-996K.

FIG. 3A shows relative adsorption of BSA and Fib on uncoated PP, ascompared to high molecular weight PDMA, PAM, PHMA, PHEA, PTHMAM, PHPMA,PMPDSAH, PMPC, PVP, PEO, HPG and dextran compositions with PDA, whereinadsorption was measured at 2 h at 37° C.

FIG. 3B shows complement activation on uncoated PP, as compared to highmolecular weight PDMA, PAM, PHMA, PHEA, PTHMAM, PHPMA, PMPDSAH, PMPC,PVP, PEO, HPG and dextran compositions with PDA, wherein samples wereincubated with fresh serum for 2 h.

FIG. 3C shows platelet adhesion on the high molecular weight hydrophilicpolymers (i.e. PDMA, PAM, PHPMA and PMPDSAH) deposited with PDA on PPsurfaces relative to that on the uncoated PP surface and PDA alone.

FIG. 3D shows normalized count of adherent S. aureus after incubation inLB containing 10⁶ starting cells/ml for 24 h as determined by the SEMimages, wherein uncoated PP and PDA only coated PP, are compared to highmolecular weight PDMA, PAM, PHMA, PHEA, PTHMAM, PHPMA, PMPDSAH, PMPC,PVP, PEO, HPG and dextran compositions with PDA.

FIG. 4A shows water contact angles of uncoated and PDMA-795K coatedsubstrates for a variety of substrates (i.e. Si, TiO₂, PP, PU, UPVC,PPVC, PI and PE).

FIG. 4B shows the thickness of high molecular weight deposited coatingson silicon surfaces after 0 days, 3 days, 1 week, 2 weeks and 3 weeks ofincubation in PBS buffer, as determined by ellipsometry.

FIG. 4C shows (c1) Ellipsometric thickness of PDMA-795K coatings onsilicon substrate after 1 cycle and 2 cycles of deposition (i.e.deposition followed by drying and subsequence second deposition andsecond drying); (c2) Water contact angle of PDMA-795K coating on PPsubstrate after 1 cycle of deposition; (c3) Water contact angle ofPDMA-795K coating on PP substrate after 2 cycles of deposition.

FIG. 5A shows a DLS study of particle formation (hydrodynamic size) in aTRIS buffered solution of dopamine and in a TRIS buffered solution ofdopamine at different molecular weight PDMA.

FIG. 5B shows force measurements of (d1) PDA-coated Si, (d2)PDA/PDMA-43K-coated Si, (d3) PDA/PDMA-213K-coated Si, (d4)PDA/PDMA-795K-coated Si, wherein representative approach (solid line)and retraction (broken line) force curves are shown.

FIG. 5C shows a schematic of a possible mechanism for PDMA-795K coatingformation onto substrate surface.

FIG. 5D shows dynamic light scattering (DLS) and TEM studies of particleformation in a TRIS buffered solution of dopamine and in a TRIS bufferedsolution of PDA with either PEO, PVP or HPG.

FIG. 5E shows force measurements of PDA combined with high molecularweight (g1) PVP, (g2) PEO, and (g3) HPG coated Si substrates, whereinrepresentative approach (solid line) and retraction (broken line) forcecurves are shown.

FIG. 6A shows adherence of S. aureus to uncoated (pristine) andPDA/PDMA-795K coated catheters (modified), wherein adherence wasassessed by the CFU method, wherein each group contains one uncoated andone coated catheter and 4 uncoated and 4 coated catheters for in vitroexperiment.

FIG. 6B shows in vivo adherence of S. aureus to uncoated andPDA/PDMA-795K coated catheters tested in a mouse model ofCatheter-associated urinary tract infection (CAUTI), to compare adherentbacteria and biofilm formation on the catheter surface when challengedwith 500,000 CFU/mL S. aureus bacteria over 7 days.

FIG. 6C shows the bacterial growth in mouse urine taken from the CAUTImice in FIG. 6B, to compare bacterial growth (CFU/mL) in the urine after7 days.

FIG. 7A shows wide scan of the high molecular weight PVP, PEO, HPG, andDextran coated silicon wafers by XPS spectra, with detailed nitrogen(N1S) Spectra of PMPDSAH and PMPC coated silicon wafers characterized byXPS spectra.

FIG. 7B shows water contact angles of uncoated PP and PDA with: HMWPDMA; HMW PAM; HMW PHMA; HMW PHEA; HMW PTHMAM; HMW PHPMA; HMW PMPDSAH;HMW PMPC; HMW PVP; HMW PEO; HPG; and Dextran, deposited PP substrates.

FIG. 8A shows normalized thickness of polydopamine and PDMA-795Kdeposited coatings on silicon wafers after 10 minutes ultrasonication inPBS buffer, as determined by ellipsometry.

FIG. 8B shows relative biofilm formation of S. aureus on 1 layer and 2layers PDA/PDMA-795K coated polypropylene films after 24 h incubation inLB medium determined by SEM images.

FIG. 8C shows relative biofilm formation of E. coli on 1 layer and 2layers PDA/PDMA-795K coated polypropylene films after 24 h incubation inLB medium determined by SEM images.

FIG. 9A shows DLS and TEM studies of particle formation in a TRISbuffered solution of dopamine and PAM, PHMA, PHEA, PTHMAM, PHPMA,PMPDSAH, PMPC, and Dextran.

FIG. 9B shows an illustration of a possible mechanism of coatingformation onto surface using different molecular weight PDA/PDMA.

FIG. 9C shows an illustration of possible mechanism of coating formationonto a substrate surface using PDA and different high molecular weighthydrophilic polymers.

FIG. 9D shows force measurements of coating 3, 43K: 30 mg/ml PDMA 2mg/ml PDA, wherein representative approach (solid line) and retraction(broken line) force curves are shown.

FIG. 9E shows force measurements of coating 5, 213K: 30 mg/ml PDMA; 2mg/ml PDA, wherein representative approach (solid line) and retraction(broken line) force curves are shown.

FIG. 9F shows force measurements of coating 7, 795K: 30 mg/ml PDMA; 2mg/ml PDA, wherein representative approach (solid line) and retraction(broken line) force curves are shown.

FIG. 10A shows a series of histograms representing the rupture distanceand adhesive force calculated from the force curves for PDA-coating,PDA/PDMA-43K-coating, PDA/PDMA-213K-coating, PDA/PDMA-795K-coating witha mix ratio of PDMA and PDA about 5:1 (30 mg/mL PDMA, 2 mg/mL PDA).

FIG. 10B shows two plots of dependence of rupture distance and adhesiveforce on the molecular weight of PDMA used in the coating with a mixratio of PDMA and PDA about 5:1 (10 mg/mL PDMA, 2 mg/mL PDA).

FIG. 10C shows two plots of dependence of rupture distance and adhesiveforce on the molecular weight of PDMA used in the coating with a mixratio of PDMA and PDA about 15:1(30 mg/mL PDMA, 2 mg/mL PDA).

FIG. 10D shows a series of histograms representing the rupture distanceand adhesive force calculated from the force curves for PDA-coating,PDA/PDMA-43K-coating, PDA/PDMA-213K-coating, PDA/PDMA-795K-coating witha mix ratio of PDMA and PDA about 15:1 (30 mg/mL PDMA, 2 mg/mL PDA).

FIG. 11 shows the chemical structures of polymeric binder monomerstested herein for substrate coating (i.e. DA: Dopamine; NE:Norepinephrine; TA: Tannic acid; PG: Pyrogallol).

DETAILED DESCRIPTION

The following detailed description will be better understood when readin conjunction with the appended figures. For the purpose ofillustrating the invention, the figures demonstrate embodiments of thepresent invention. However, the invention is not limited to the precisearrangements, examples, and instrumentalities shown.

Any terms not directly defined herein shall be understood to have themeanings commonly associated with them as understood within the art ofthe invention.

The term “high molecular weight polymer” or HMW polymer as used hereinrefers to any polymer having a molecular weight ≥100,000 daltons (i.e.greater than and equal to 100 kDa) and in particular refers to thehydrophilic polymers described herein.

As used herein “uniformity” refers to the thickness of the coatingformed over the entire surface of the substrate to which the coatingcompositions described herein were applied. The term implies that thereis a consistency over the entirety of the substrate surface in terms ofcomposition (i.e. polymeric binder and hydrophilic polymer) and theoverall thickness of the coating and thus has implications for thesmoothness of the coating.

The term “polymeric binder” as used herein is meant to encompasscatechol and catechol derivative polymers encompassed by Structure I,wherein Structure I is represented by

wherein, D¹ may be selected from H, OH,

D² may be selected from H, OH,

D³ may be selected from H, OH,

D⁴ may be selected from H, OH,

wherein E¹ and E² may be selected from H or

For example, a polymeric binder may be a polymeric dopamine (PDA), apolymeric norepinephrine (PNE), a polymeric epinephrine (PEPI), apolymeric pyrogallol (PPG), a polymeric tannic acid (PTA), a polymerichydroxyhydroquinone (PHHQ), a polymeric catechin, or a polymericepigallocatechin.

As used herein a “hydrophilic polymer” is meant to encompasspolyacrylamides, polymethacrylamides and polymethacrylates havingStructure II, wherein Structure II is as follows:

wherein, G may be H or CH₃. R may be selected from

and m may be an integer between 400 and 5,000,000. Alternatively, ahydrophilic polymer may be an acrylate, an acrylamide, a methacrylate ora methacrylamide with hydroxyls, amides, substituted amides, sulfhydryl,zwitter ions in the pendent chains where degree of polymerization (m) isbetween 400 and 5,000,000. Alternatively, a hydrophilic polymer may bean acrylate, an acrylamide, a methacrylate or a methacrylamide whereindegree of polymerization (m) is between 400 and 5,000,000.

The term “biofilm” is used herein as it is normally understood to aperson of ordinary skill in the art and often refers to any group oforganisms adhering to the surface of a structure.

The term “biofouling” is used herein as it is normally understood to aperson of ordinary skill in the art and often refers to the colonizationof an interface by organisms, which often leads to deterioration of theinterface.

The term “antifouling” is used herein as it is normally understood to aperson of ordinary skill in the art and often refers to the reduction offormation of biofilms and biofouling.

The term “thrombus” is used herein as it is normally understood to aperson of ordinary skill in the art and often referred to as blood clot,as the product of blood coagulation steps in hemostasis.

The term “primer” as used herein is meant to encompass any coatingapplied to a substrate before a subsequent composition is applied. Theprimer may act to prepare the surface of the substrate or facilitate theapplication of an subsequent composition to the substrate.

The term “plastic” as used herein is meant to encompass a vast number ofsynthetic or semi-synthetic organic polymers that are malleable and maybe molded into solid forms. Exemplary plastics are: Polyester (PES);Polyethylene terephthalate (PET); Polyethylene (PE); High-densitypolyethylene (HDPE); Polyvinyl chloride (PVC); Polyvinylidene chloride(PVDC); Low-density polyethylene (LDPE); Polypropylene (PP); Polystyrene(PS); High impact polystyrene (HIPS); Polyamides (PA) (Nylons);Acrylonitrile butadiene styrene (ABS); Polyethylene/AcrylonitrileButadiene Styrene (PE/ABS a blend of PE and ABS); Polycarbonate (PC);Polycarbonate/Acrylonitrile Butadiene Styrene (PC/ABS a blend of PC andABS); Polyurethane (PU); Polylactic acid (PLA); Polyimide;Polyetherimide (PEI); Polyetheretherketone (PEEK); phenol formaldehydes(PF); and Polymethyl methacrylate (PMMA).

The term “polydopamine (PDA)” is used herein as it is normallyunderstood to a person of ordinary skill in the art and often refers tothe pH-dependent self-polymerization of dopamine. However,“polydopamine” may be formed by any polymerisation of dopamine monomers.It should be noted that the mechanism of PDA formation is currently notunderstood (Dreyer, D. R. et al., 2013; Lynge, M. E. et al., 2011).Furthermore, it should be noted that the structure of the polymerproduct has not been elucidated yet (Dreyer, D. R. et al., 2013).

The term “hydrophilic polymer” is used herein as it is normallyunderstood to a person of ordinary skill in the art and often refers toa polymer containing polar or charged functional groups, rendering themsoluble in water.

The term “PAM” is used herein as it is normally understood to a personof ordinary skill in the art and often refers to poly(acrylamide).

The term “PDMA” is used herein as it is normally understood to a personof ordinary skill in the art and often refers to poly(N,N-dimethylacrylamide).

The term “PHMA” is used herein as it is normally understood to a personof ordinary skill in the art and often refers to “poly(N-hydroxymethylacrylamide)”.

The term “PHEA” is used herein as it is normally understood to a personof ordinary skill in the art and often refers to “poly(N-hydroxyethylacrylamide)”.

The term “PTHMAM” is used herein as it is normally understood to aperson of ordinary skill in the art and often refers to“poly{N-[tris(hydroxymethyl) methyl]acrylamide}”.

The term “PMA” is used herein as it is normally understood to a personof ordinary skill in the art and often refers to “poly(methacrylamide)”.

The term “PHPMA” is used herein as it is normally understood to a personof ordinary skill in the art and often refers to“poly(N-(2-hydroxypropyl)methacrylamide)”.

The term “PMPDSAH” is used herein as it is normally understood to aperson of ordinary skill in the art and often refers to“poly(N-(3-(methacryloylamino)propyl)-N,N-dimethyl-N-(3-sulfopropyl)ammonium hydroxide)”.

The term “PMPC” is used herein as it is normally understood to a personof ordinary skill in the art and often refers to“poly(2-methacryloyloxyethyl phosphorylcholine)”.

The term “PVP” is used herein as it is normally understood to a personof ordinary skill in the art and often refers to “poly(vinylpyrrolidone)”.

The term “PEO” is used herein as it is normally understood to a personof ordinary skill in the art and often refers to “poly(ethylene oxide)”.

The term “HPG” is used herein as it is normally understood to a personof ordinary skill in the art and often refers to “hyperbranchedpolyglycerol”.

The term “Dextran” is used herein as it is normally understood to aperson of ordinary skill in the art and often refers to “branched glucancomposed if chains of varying length”.

The term “PP” is used herein as it is normally understood to a person ofordinary skill in the art and often refers to “poly(propylene)”.

The term “PU” is used herein as it is normally understood to a person ofordinary skill in the art and often refers to “poly(urethane)”.

The term “PE” is used herein as it is normally understood to a person ofordinary skill in the art and often refers to “poly(ethylene)”.

The term “uPVC” is used herein as it is normally understood to a personof ordinary skill in the art and often refers to “unplasticizedpolyvinyl chloride”.

The term “pPVC” is used herein as it is normally understood to a personof ordinary skill in the art and often refers to “plasticized polyvinylchloride”.

The term “PI” is used herein as it is normally understood to a person ofordinary skill in the art and often refers to “poly(imide)”.

The term “EVA” is used herein as it is normally understood to a personof ordinary skill in the art and often refers to “ethylene vinylacetate”.

The term “Teflon” is used herein as it is normally understood to aperson of ordinary skill in the art and often refers to“poly(tetrafluoroethylene) or PTFE”.

The term “coating” is used herein as it is normally understood to aperson of ordinary skill in the art to be a covering that is applied tothe surface of an object and is to be broadly constructed to includeadhesive coating, resistive coating (e.g., resistive to cellularadhesion), and protective coating. The present invention offers adhesionin “highly humid” environments (50% to 80% humidity) and “wet”,“saturated”, or “super-saturated” environments (at least 80% humidityand higher). Adhesion under dry environment is also contemplated herein.

The term “dip-coating” is used herein as it is normally understood to aperson of ordinary skill in the art and often refers to the immersion ofthe substrate into the solution of the coating material.

The term “lubricity” is used herein as it is normally understood to aperson of ordinary skill in the art and often refers to the property of“slipperiness” or “smoothness”, or “a surface with low friction”.

The coating described herein has high lubricity. These coatings areuseful for medical devices where their lubrication results in reducedfrictional forces when the device is introduced and moved within thebody, reducing inflammation and tissue trauma as well as supportingpatient comfort.

Various alternative embodiments and examples are described herein. Theseembodiments and examples are illustrative and should not be construed aslimiting the scope of the invention.

MATERIALS AND METHODS

Polymer Synthesis and Characterization: The high molecular weightpolymers were synthesized by aqueous ATRP. Molecular weight andpolydispercity index (PDI) of polymers were determined by using GPC on aWaters 2690™ separation module fitted with a DAWN EOS™ multi-angle laserlight scattering detector from Wyatt Technology Corp.™ with 18 detectorsplaced at different angles and a refractive index detector (Optilab DSP™from Wyatt Technology Corp.™) An Ultrahydrogel™ linear column with abead size of 6-13 μm (elution range 10³ to 5×10⁶ Da) and anUltrahydrogel 120™ with a bead size of 6 μm (elution range 150 to 5×10³Da) from Waters™ were used. The dn/dc value of high molecular weightpolymers in the mobile phase was determined at λ=620 nm and was used fordetermining molecular weight parameters. The number-average mean squareradius moments were taken as the radius of gyration of the polymer.

Surface Modification: The silicon wafer and titanium dioxide wereexposed to oxygen plasma for 4 min to remove adventitious contamination.Other polymer substrates were cleaned by sonication in deionized waterfor 10 min and blow-dried under a stream of nitrogen gas. For surfacemodification, a mixture of 2 mg/ml dopamine and 10 mg/ml polymer wasprepared in 10 mM Tris buffer (pH=8.5). The substrates were thenimmersed in dopamine or polymer/dopamine solution and kept for 24 hwithout stirring. Afterwards, the modified samples were rinsed withdeionized water and dried in a steam of nitrogen gas.

Characterization of Particle Formation: Dynamic light scattering (DLS)measurements of the polymer solution (0.16 mg/ml in ultra-pure water)were performed using a Zetasizer NanoZS™ instrument (MalvernInstruments™) at the end the reaction. Each measurement was repeated for3 times, and the averaged value was accepted as the final hydrodynamicsize (Dh). The measurements were performed with an equilibration time of1 min at room temperature. The nanoparticles in polymer solution werealso viewed on a H7600 PC-TEM™ (Hitachi™) at an accelerating voltage of80 KV, and images were recorded with an Advantage HR digital CCD camera(Advanced Microscopy Techniques™). UV-Vis spectra were recorded at roomtemperature in a Varian Cary 4000™ spectrophotometer using a 1 cm pathlength quartz cell.

Surface Characterization: Attenuated Total Reflectance Fourier TransformInfrared (ATR-FTIR) spectra were recorded using a Thermo-Nicolet NexusFTIR™ spectrometer (Nicolet Instrument™, Waltham, Mass.) with a MCT/Aliquid nitrogen cooled detector, KBr beam splitter and MKII Golden GateSingle Refection ATR™ accessory (Specac Inc.™ Woodstock, Ga.). Spectrawere recorded at 4 cm⁻¹ resolution and 64 scans were collected for eachsample. PP films were used as the background to obtain the subtractedspectra. For static water contact angle measurements, digital images ofa 5 μL water droplet on the surface were taken using a Retiga 1300 ™digital camera (Q-imaging Co.™), and analyzed using Northern Eclipse™software. Six different spots on the PP film were tested for each sampleand the average value is reported. The variable-angle spectroscopicellipsometry (VASE) spectra were collected on an M-2000 V™ spectroscopicellipsometer (J. A. Woollam™, Lincoln, Nebr.) at 55, 65, and 75° atwavelengths from 480 to 700 nm with an M-2000 50W quartz tungstenhalogen light source. The VASE spectra were then fitted with amultilayer model utilizing WVASE32 analysis software based on theoptical properties of a generalized Cauchy layer to obtain the drythickness of the deposited layers. X-ray photoelectron spectroscopy(XPS) was performed using a Leybold LH Max 200™ surface analysis system(Leybold™, Cologne, Germany) equipped with a Mg Kα a source at a powerof 200 W. Elements were identified from survey spectra. High-resolutionspectra were collected at 48 eV pass energy. Atomic force microscopy(AFM) measurements were performed on a commercially available multimodesystem with an atomic head of 130×130 μm² scan range which used aNanoScope IIIa™ controller (Digital Instruments™, Santa Barbara,Calif.). Surface morphology was examined under PBS buffer in contactmode using a commercially manufactured V-shaped silicon nitride (Si₃N₄)cantilever with gold on the back for laser beam reflection (Veeco™,NP-S20™). The spring constant of the AFM cantilever was measured usingthe thermal equipartition theorem. Force measurements were performed inPBS buffer. On tip approach the onset of the region of constantcompliance was used to determine the zero distance, and on retractionthe region in which force was unchanged was used to determine the zeroforce. The rate of tip-sample approach or retraction was typically 1μm/s. The raw AFM force data were converted into force vs. separationusing custom Matlab™ v.5.3 software. The software converts thecantilever deflection vs. linear voltage displacement transformer signalinto restoring force vs. tip-substrate separation using user inputtrigger and spring constant values. We followed our published protocolfor the calculation of the adhesive force.

Protein Adsorption: To determine the extent of absorbed protein on thePP film, the samples were incubated with BSA-FITC conjugate orFib-Alex-fluor 594™ conjugate buffer. 1 mg/ml BSA conjugate and 0.25mg/mL Fib conjugate was prepared in PBS buffer. Before incubation withprotein solutions, the samples were equilibrated with PBS for 10 min.Afterwards, the substrates were incubated with 0.3 mL stock solutionsfor 2 h, thoroughly washed with PBS buffer for 3 times and dried in asteam of nitrogen. The images of protein-absorbed samples were takenusing a fluorescence microscope.

Blood Collection: Blood was provided from donors at the Centre for BloodResearch by an approved protocol by The University of British Columbia™clinical ethics committee. Blood was collected in in serum tubes. Buffycoat Platelet-rich plasma (PRP) was obtained from Canadian BloodServices™. Serum was prepared by centrifuging whole blood containingserum tube at 1200* g for 30 min.

Complement Activation: Two sets of samples each equilibrated with PBSwere used for this assay. Both sets of samples were incubated with freshhuman serum for 2 h at 37° C. and washed with PBS to remove any looselyadhered proteins. The first set of samples was incubated with FITClabeled anti-C3b antibody for 2 h and washed with PBS. The second set ofsamples was incubated with FITC Mouse IgG1 isotype control for 2 h andwashed with PBS. All the dried samples were viewed under a fluorescentmicroscope. The samples without serum incubation were also examined ascontrols.

Platelet Adhesion: The level of platelet adhesion on different coatingswas quantified by SEM analysis. All samples were incubated in buffy coatPRP in a 24-well plate under static condition at 37° C. After 4 h, thesamples were taken out and carefully washed with PBS and fixed with 2.5%glutaraldehyde for 2 h at 4° C. After serial dehydration with 50%, 60%,70%, 80%, 90%, and 100% ethanol for 10 min each, the samples were dried,coated with a thin layer of Au, and observed under SEM. The number ofplatelet on the samples was quantified by counting the total numberadhered platelet from at least 6 representative images at the samplemagnification (×1000). The results obtained from the coated samples werenormalized using the adhered number from original PP films.

Initial Bacterial Adhesion: For initial bacterial adhesion assay,different sterilized coatings were grown on a 96-well PP plate.Overnight culture of bacteria (S. aureus) was first adjusted to 10⁶CFU/ml in LB. Each well was equilibrated with LB for 10 min and thencoved with 0.2 ml bacterial suspension. The inoculated plate wasincubated for 4 h at 37° C. After the bacterial adhesion process, thewells were filled with PBS and washed 3 times to remove non-adherentbacteria. The wells with adhered bacteria were ultrasonicated for 10 minto release bacteria cells into PBS (0.2 ml). The bacterial suspensionwas serially diluted and spread on an agar plate. After culturingovernight, the number of viable bacterial cells was quantified bycounting the number of colonies on the agar plate.

Biofilm Formation: S. aureus and E. coli biofilm were tested onunmodified and modified PP samples. The sterilized samples were cut intopieces and transferred into a 48-well plate. Overnight culture ofbacteria was first adjusted to 10⁶ CFU/ml in LB. Each sample wasequilibrated with LB for 10 min and then immersed in 0.6 ml S. aureusculture. The 48-well plate was incubated at 37° C. with shaking at 50rpm. After 24 h incubation, suspension was removed and the samples werethoroughly washed with PBS to remove loosely adhered bacteria. For theassessment of adhered bacteria on samples, SYTO 9™, a green-fluorescentnucleic acid staining agent, was used to label all the bacterial cellsby penetrating cell membranes. The washed samples were soaked in a dyesolution at room temperature in the dark for 15 min. The stainedbacterial cells were viewed under a fluorescent microscope. For SEManalysis, the samples were taken out and fixed with 2.5% glutaraldehydefor 2 h at 4° C. After serial dehydration with 50%, 60%, 70%, 80%, 90%,and 100% ethanol for 10 min each, the samples were dried, coated with athin layer of Au, and observed under SEM. The number of bacteria on thesamples was quantified by counting the total number adhered plateletfrom at least 6 representative images at the sample magnification(×5000). The results obtained from the coated samples were normalizedusing the adhered number from original PP films.

Stability of the Coating: The stability of the coatings in physiologicalsolution was monitored by thickness change. The samples were incubatedin PBS buffer for different periods (3 days-3 weeks) before measuringthe thickness change on silicon wafers.

Catheter Evaluation: PU catheters were cut into 1-cm segments and coatedwith the optimized PDMA coating. All samples were sterilized with 70%ethanol. Unmodified and modified samples were rinsed with PBS to get ridof excess ethanol. Overnight cultures were diluted in LB to aconcentration of approximately 1^(x) 10⁶ CFU/ml, and 1 ml was added to1.5 ml Eppendorf™ tubes. Cultures were incubated at 37° C. with shakingat 50 rpm for 6 hours. After incubation, samples were rinsed with PBSfor 3 times to remove nonadherent organisms, and added to 1 ml PBS. Thesamples were ultrasonicated for 10 min in water bath and followed byvortexing for 10 s. Dilutions in sterile PBS were grown on agar platesto determine CFU/catheter.

In Vivo Mouse Model: Prior to the animal procedure, a 24G angio-catheter(B&D™, Mississauga, Ontario, Canada) was modified under strict asepticconditions to “load” the catheter piece to be inserted into the bladderonto the needle. Animals underwent inhalational anesthesia with 3%isofluorane and were positioned on their back on a heating pad. Alllimbs were secured using tape, the abdomen was shaved and prepped withchlorhexidine and sterile ultrasound gel was applied. The bladder wasvisualized using a Vevo 770™ high frequency ultrasound system(VisualSonics™, Toronto, ON, Canada) and the needle-mounted modified 24Gangiocatheter was positioned at a 30° angle just above the pubic bonewith the bevel directed anteriorly. After ultrasonic visualization ofthe needle, it was inserted towards the bladder. Once the isolated 4 mmsegment was visualized inside the bladder, the needle was removedleaving only the short FEP segment in the lumen. The entire process wasvisualized in real-time under ultrasonic guidance. All animals received2 mg/kg meloxicam (Metacam™, Boehringer Ingelheim™, Burlington, ON,Canada) subcutaneously before they were recovered from anesthesia.

One day following catheter implantation, animals were anesthetized againand 5×105CFU/mL S. aureus in 50 μl of PBS was percutaneously injectedinto the bladder utilizing a 30G needle under ultrasound guidance.Negative controls were injected with PBS only using the same procedure.Animals were recovered from anesthesia after a dwell time of 30 min. Theamount of the bacterial inoculum was confirmed by serial dilutions andCFU counts on Luria Bertani (LB) agar incubated overnight at 37° C.Animals were recovered for 7 days, at which point they were euthanizedand the catheter pieces were removed and biofilm formation was assessedvia CFU counts following sonication to remove adherent bacteria.

EXAMPLES Example 1: Preparation of Binary Coating

The polymers used in this study are commercially available or have beensynthesized by aqueous atom transfer radical polymerization (ATRP). Gelpermeation chromatography (GPC) was used to determine the molecularweight and polydispersity (PDI) of the polymers (TABLE 1). The one-stepdeposition consists of two basic components: a hydrophilic polymer anddopamine. The polymers are co-dissolved with dopamine-hydrochloride in apH=8.5 solution, in which the substrates are immersed at roomtemperature in air (FIG. 1A).

TABLE 1 Characteristics of the hydrophilic polymer used in this study,including dry thickness of the deposited film on silicon wafer:Thickness Polymer Mn Mw PDI Rh (nm) (nm) PDA 32.2 ± 0.1 *PDMA   43K 102K 2.38 8.9 33.8 ± 0.4 *PDMA  146K  209K 1.43 13.0 21.9 ± 0.4 *PDMA 213K  356K 1.67 15.5 20.8 ± 0.1 *PDMA  412K  555K 1.35 20.4 18.3 ± 0.6*PDMA  795K 1260K 1.58 28.1 18.9 ± 1.3 *PDMA  996K 1290K 1.30 29.2 17.7± 0.4 *PAM  441K  614K 1.39 21.4 20.7 ± 0.2 *PHMA  503K 1200K 2.38 19.712.0 ± 0.1 *PHEA  932K 1290K 1.38 33.4 16.0 ± 0.1 *PTHMAM  632K 1050K1.66 21.7  8.9 ± 0.1 *PHPMA  824K 1150K 1.39 24.2 24.5 ± 0.2 *PMPDSAH 968K 1160K 1.19 16.2 12.5 ± 0.2 *PMPC 1310K 1600K 1.22 28.4 12.7 ± 0.1*PVP ND 1300K ND ND  2.3 ± 0.2 *PEO ND  900K ND ND 8.2 ± 0.4 *HPG  703K 865K 1.23 ND 14.6 ± 0.2  *Dextran  705K 1190K 1.68 ND 16.8 ± 0.2  *withPDA

Example 2: Dependence of the Molecular Weight of the Polymer on thePhysical and Biological Properties of the Coating

Silicon wafer was used as a model surface determining the properties ofthe coating and study the polymerization of process. PDMA havingdifferent molecular weights ranging from 43K Da to 996K Da (TABLE 1) wasused for the preparation of the coating. Small pieces of silicon waferwere immersed in a solution of the polymer and dopamine at roomtemperature for 24 h without stirring and were rinsed thoroughly withtris-buffered saline and water followed by drying in a flow of argongas. Ellipsometry measurements were used for the determination of thethickness of the coating. PDA gave a dry thickness of 32.2±0.1 nm on thesurface. The binary coating prepared by mixing PDMA and dopamine gavethicknesses in the range from 17.7 to 33.8 nm (TABLE 1). The thicknessof the coating decreased with increasing molecular weight of the PDMAused.

The chemical composition of the deposited coating was determined usingXPS analysis. A comparison of PDA coating and binary PDA-PDMA coating isshown in FIG. 2A and TABLE 2A. Similarly, a comparison of high molecularweight PVP, PEO, HPG, and Dextran coated silicon wafers by XPS spectrais shown in FIGURE 7A and TABLE 2B. The intensity of the nitrogen peakincreased with increasing molecular weight of the PDMA. The coatingprepared using the PDMA 795K showed higher intensity of nitrogen andlower intensity of oxygen, indicating more PDMA was incorporated intothe coating. This fact was also verified from the increased intensity ofC=O component in the C is detail spectrum of the coating prepared usinghigh molecular weight PDMA. Further characterization of the coating wasperformed using contact angle measurements and ATR-FTIR measurements.

TABLE 2A Comparison of chemical compositions of various depositedcoatings on silicon wafers based on X-ray Photoelectron Spectroscopy(XPS) Analysis. POLYMER Si (AT %) C (AT %) N (AT %) O (AT %) N/O N/C O/CPDA only 0.72 70.09 7.73 21.46 0.360 0.110 0.306 *PDMA43K 1.19 72.508.20 18.11 0.453 0.113 0.250 *PDMA213K 0.82 71.16 10.21 17.81 0.5730.143 0.250 *PDMA795K 0.45 71.67 10.67 17.21 0.620 0.149 0.240 *with PDA

TABLE 2B Comparison of chemical compositions of various depositedcoatings on silicon wafers based on X-ray Photoelectron Spectroscopy(XPS) Analysis. POLYMER Si C N O S P N/O N/C O/C Silicone only 50.659.38 0 39.97 0 0 0 0 4.26 *PMPDSAH 4.51 64.07 7.38 20.74 3.30 0 0.360.12 0.32 *PMPC 3.53 63.23 5.97 25.13 0 2.14 0.24 0.09 0.40 *PVP 31.4137.75 5.66 25.28 0 0 0.22 0.15 0.67 *PEO 13.80 55.87 5.63 24.70 0 0 0.230.10 0.44 *HPG 1.64 64.27 3.75 30.34 0 0 0.12 0.06 0.47 *DEXTRAN 1.0764.76 5.53 28.63 0 0 0.19 0.09 0.44 *with PDA

After successful preparation of the coating on silicon surface, asimilar protocol was used to prepare a coating on polypropylene (PP)film. The binary coating on the PP surface was evidenced from the staticwater contact angle and ATR-FTIR analyses. Coating of the PP substratewith binary coating led to a considerable decrease in the static watercontact angle from 73° for the bare PP film to 29° for the binarycoating that used 996 K PDMA (FIG. 2B). Similarly, FIG. 7B shows watercontact angles of uncoated PP as compared to PDA/PDMA, PDA/PAM,PDA/PHMA, PDA/PHEA, PDA/PTHMAM, PDA/PHPMA, PDA/PMPDSAH, PDA/PMPC,PDA/PVP, PDA/PEO, PDA/HPG and PDA/Dextran deposited PP substrates. Thedecrease in static water contact angle represents a decrease inhydrophobicity of the coating. ATR-FTIR spectra also providedinformation on the chemical compositions of the coatings. The pure PDAcoating showed two distinctive peaks at 1617 cm⁻¹ and 1510 cm⁻¹, whichwere attributed to the overlap of the C=C vibrations in the aromaticring and the N-H bending vibrations, respectively. An increase inabsorbance at 1622 cm⁻¹ was seen for the binary PDA-PDMA coating,demonstrating the incorporation of PDMA component into the coating.

The initial screening of antifouling properties of the binary coating(i.e. PDA) prepared from different molecular weight PDMAs on PP filmswere tested using single protein adsorption and biofilm formation. Theability to resist nonspecific protein adsorption was tested byincubating the unmodified (i.e. PP only), PDA coated PP, PDA/PDMA-43Kcoated, PDA/PDMA-146K coated, PDA/PDMA-213K coated, PDA/PDMA-412Kcoated, PDA/PDMA-795K coated and PDA/PDMA-996K coated PP surfaces with0.25 mg/ml fibrinogen (Alex Fluor-594 conjugate) and FITC labeled-BSAfor 2 h, and then thoroughly washing. The coating was evaluated byfluorescence microscopy measurements taken before protein incubation andafter incubation. Fluorescently labeled proteins, FITC labeled-BSA andAlex Fluro594 fibrinogen (Fib), were used for evaluation (micrographsnot shown). The high molecular weight PDMA-996K deposited surfacesignificantly reduced the BSA and Fib adsorption compared to unmodifiedsamples, as evident from 95.0% and 88.7% reduction in fluorescenceintensity (FIG. 2C) reflecting the performance of the coating and thedependence on the molecular weight.

To screen the anti-biofilm performance of polymer coatings, theunmodified (i.e. PP only), PDA coated PP, PDA/PDMA-43K coated,PDA/PDMA-146K coated, PDA/PDMA-213K coated, PDA/PDMA-412K coated,PDA/PDMA-795K coated and PDA/PDMA-996K coated PP surfaces were incubatedwith S. aureus suspension for 24 h. The number of bacteria that adheredon the surface was determined by SEM analysis and CFU counts images. TheSEM analysis revealed (micrographs not shown) very few S. aureus cellsadhered on the coating prepared using high molecular weight PDA/PDMAwhereas large amount of S. aureus cells were found on both unmodified PPand PDA coated PP surfaces. In particular, PDA/PDMA-795K coated andPDA/PDMA-996K coated PP surfaces showed a reduction in biofilm formationof S. aureus cells by 99.3% and 99.2% (FIG. 2D), respectively comparedto pristine PP surface. Similarly, relative bacterial adhesion of S.aureus on uncoated PP, PDA coated PP, high molecular weight PDMA, PAM,PHMA, PHEA, PTHMAM, PHPMA, PMPDSAH, PMPC, PVP, PEO, HPG and dextrancompositions with PDA are shown after 24 (FIG. 3D). Consistently, theleast S. aureus bacterial adhesion was shown with coatings of PDA witheither PDMA, PAM, PHMA, PHEA or PHPMA, wherein the hydrophilic polymerwas a high molecular weight polymer.

Further long term biofilm studies with S. aureus lux: uncoated TiO₂ andcoated (PDMA-795 k/PDA) (5:1) TiO₂ were placed on 24-well plates in atotal volume of 1 ml Tryptic Soy Broth (TSB) culture containing 500,000cells/ml was added to each well. After every 24 hours, suspension wasremoved and new TSB culture with 500,000 cells/ml was added. At days 3and 7, the samples were thoroughly washed and the fluorescent stainSyto-9™ was used to microscopically assess the surface-attached biomass.The samples were anayzed using a confocal laser scanning microscope.

Visulization of the uncoated sample demostrated S. aureus biofilmformation after 3 days. However, the coated surfaces demostratedmarkedly delayed surface colonization, with very few bacteria on thesurface on day 3. Similar observations were made on day 7, where biofilmformation was significantly reduced on coated sample relative to that ofuncoated sample.

Example 2: Dependence on Polymer Chemistry of the Properties of theCoatings

The coating technique was adapted to other high molecular weighthydrophilic polymers. As shown in (FIG. 1B), a small library of twelvehydrophilic polymers with high molecular weight was selected to providewide chemical diversity, including linear neutral polymers, linearzwitterionic polymers, and branched polymers. The molecular weight ofthe polymers ranged from 441 k to 1310 k and hydrodynamic size rangingfrom 16.2 nm to 29.2 nm. The deposition of different polymers assistedby dopamine was first examined on the silicon wafers. PVP, PEO, andPTHMAM were among the thinnest layers with values of 2.3±0.2 nm, 8.2±0.4nm, and 8.9±0.1 nm, respectively, while other polymer coatings gavelayers around 12.0 nm-24.5 nm (TABLE 1). The X-ray photoelectronspectroscopy (XPS) wide scans, S 2p or P 2p core-level spectra of thePMPDSAH and PMPC coatings were measured (data not shown). As expected,the sulfur (S) peak was detected in PMPDSAH coated sample and phosphorus(P) peak was detected in PMPC coated sample, demonstrating theincorporation of these polymers. Furthermore, a nitrogen peak appearedat 403.0 eV, which was attributed to the cationic nitrogen in thezwitterionic polymers, was detected in both PMPDSAH and PMPC coatedsamples, confirming the deposition of these hydrophilic polymers. In thecase of HPG and Dextran coated samples, an overall increase of oxygenwas visible in widescan mode, indicating the successful incorporation ofthese hydrophilic polymers. The PEO incorporated coatings behaveddifferently than HPG and Dextran coatings, showing no change on theintensity of oxygen compared to PDA coating indicating the poorincorporation of PEO on the surface coating. The difference in watercontact angle of PDA and high molecular weight polymer coated PP filmsalso provided evidence that most of the high molecular weight polymerswere incorporated into the coatings. Other than PEO and PVP coatings, adecrease in static water contact angle was observed for all othercoatings compared to the pure PDA coating. In addition, the depositedhydrophilic polymers could be clearly detected by ATR-FTIR spectra on PPfilms.

To investigate the antifouling performance of coatings with diversechemical compositions, unmodified and modified PP films were analyzedfor protein adsorption, complement protein binding, platelet adhesion,and biofilm formation. Compared to control PP films, most of the PPfilms coated with binary coating composed of hydrophilic high molecularweight polymers were able to strongly reduce the adsorption of bothproteins. In the case of PDMA, PAM, and PHPMA coated samples, the BSAand Fib adsorptions on these modified samples were only approximately 5%and 10% compared to the controls (FIG. 3A). The complement protein (C3)determined based on intensity of anti-C3b adsorption of the surface isshown in FIG. 3B, wherein the polymers containing —OH groups inducedsignificant antibody binding compared to the other polymers and controlsamples. Accordingly, PHMA, PHEA, PTHMAM and PHPMA would not likely bechosen as the hydrophilic polymer, where the substrate to be coated isintended for contact with blood or fractions thereof. The ability of thecoatings to prevent platelet adhesion was also tested, wherein SEMimages of uncoated, PDA coated, PDA with HMW PDMA, PAM, PHPMA andPMPDSAH PP substrates were examined platelet adhesion after incubationwith buffy-coated PRP for 4 h. (micrographs not shown). The binarycoating composed PDA and HMW hydrophilic polymers (i.e. PDMA, PAM, PHPMAand PMPDSAH) reduced the platelet adhesion dramatically compared to thecontrol PP surface. Compared to uncoated PP substrate, the number ofadhered platelets decreased by 95.4%, 88.2%, 96.6%, and 89.5% on PDMA,PAM, PHPMA, and PMPDSAH based coatings, respectively (FIG. 3C).

As discussed briefly above, the biofilm formation on the coatings andthe influence of chemistry of the polymers were also investigated.Incubation of S. aureus in Luria Bertani (LB) medium for 24 h led to theformation of a thick biofilm on unmodified PP substrate, whereassignificantly reduced biofilm formation was detected on binary coatingprepared from hydrophilic polymers (FIG. 3D). Differences were detectedbetween the different polymers used for the coating showing that thechoice of the hydrophilic polymer in the coating is of importance. Inparticular, PDA combined with certain HMW hydrophilic polymers (i.e.PDMA, PAM, PHMA, PHEA and PHPMA) showed the best reduction in bacterialadhesion for S. aureus.

Example 3: Universality of the Approach and Stability of the Coating

The performance of the coating prepared using 795K PDMA and PDA wastested on a variety of substrates (i.e. TiO₂, polypropylene (PP),polyurethane (PU), polyethylene (PE), unplasticized polyvinyl chloride(uPVC), plasticized PVC (pPVC) and polyimide (PI)). All substrates wereimmersed in solutions containing dopamine and 795K PDMA. After thecoating process the wettability changes of the substrates were measuredvia water contact angle measurements. Coatings on all the substratesshowed significant decrease in water contact angle compared to theuncoated surfaces (FIG. 4A) except SiO₂. Similarly, the proteinadsorption and biofouling measurements showed excellent resistantagainst protein and bacterial adhesion. Accordingly, the results suggestthat the combination of HMW PDMA and PDA is useful for coating a widerange of substrates and provides significant resistance against proteinand bacterial adhesion.

The stability of the coating was investigated by measuring the thicknessof the coating prepared on silicon wafer stored over extended periods oftime in PBS buffer (pH 7.4) (up to 3 weeks), wherein different HMWhydrophilic polymers combined with PDA were compared (i.e. PDMA, PAM,PHPMA, PMPDSAH and dextran) to PDA alone. Results shown in FIG. 4Bindicate that no significant changes in thickness upon storage.Furthermore, the stability of the coating after 10 minutes sonicationwas studied, which showed a slight decrease in the thickness (˜10%reduction), however, this change did not result in any increase inbio-adhesion by the coating.

The possibly of multilayer coating on the substrates to increase thethickness of the coating was also investigated. The studies showed thateven after incubating over 24 h with the PDMA 795 and dopamine solution,the dry thickness of the coating never increased beyond 20 nm indicativeof a uniform deposition of the particles and uncontrolled aggregation ofthe particles. Thus to increase the coating thickness, after initialdrying of the coating, an additional layer of PDA-PDMA was deposited onthe surface using similar methodology. As shown in FIG. 4C, thethickness of the initial layer was about 19 nm and nearly doublethickness of the coating was obtained upon the addition of second layer.This potentially increased the robustness and the possibility ofachieving desired thickness by controlling the dip coating process. Acomparison of S. aureus and E. coil adhesion to uncoated PP substratewith 1 layer of PDA/PDMA-795K coated PP substrate and 2 layers ofPDA/PDMA-795K coated PP substrate were tested. Although both single anddouble coated substrates showed a vast improvement in bacterialadhesions, the double layer coating had slightly improved biofilmresistant properties compared to the single layer coating (see FIGS. 8Band 8C).

Example 4: Mechanism of the Deposition Process and the FormationAntifouling Coating

The results from the antifouling analyses demonstrated that themolecular weight and chemistry of the hydrophilic polymer used in thebinary coating (i.e. polymeric binder and hydrophilic polymer) play animportant role that determine the properties of the coating. Aself-assembly process is involved in the formation polydopaminedeposition on the surface. To investigate the mechanism of the coatingprocess, the formation of PDA particles in presence of PDMA withdifferent molecular weights (i.e. 43K, 146K, 213K, 412K, 795K and 996K)were investigated. The hydrodynamic size of the particles was measuredusing dynamic light scatting (DLS) and the size of the dry particles wasmeasured using transmission electron microscopy (TEM) analysis. Theaverage hydrodynamic size of the PDA in the absence of the polymer wasaround 4000 nm. PDA particles were highly unstable and resulted inaggregation. However, upon the addition of different molecular weight ofthe PDMA, particle size was significantly decreased (see TABLE 3). Therewas an initial decrease in particle size and then it increased withincreases in molecular weight of the PDMA component (see FIG. 5A). Thestability of the particles increased with increase in molecular weightof PDMA used. Similarly, hydrodynamic size and PDI were compared forPAM, PHMA, PHEA, PTHMAM, PHPMA, PMPDSAH, PMPC, and Dextran (see FIG.9A).

TABLE 3 Number-averaged particle size of DPA and DPA/PDMA 1:5 ratio inpH 8.5 TRIS Buffered solution after 24 hours as determined by TEMAVERAGE PAR- SD SWELLING SAMPLE TICLE SIZE (NM) (NM) RATIO PDA 4343.63330.3 0.958 PDMA-43K 301.9 36.4 1.247 PDMA-213K 113.2 25.5 2.332PDMA-795K 127.6 17.1 2.701

TEM studies showed that particles formed in solution were uniformcompared to the highly aggregated particles formed in the case of PDAalone (micrographs not shown). High molecular weight PDMA preventedspontaneous aggregation and cross-linking of PDA particles and theparticle size decreased with increase in molecular weight of PDMAchains. Particle size obtained in the case of PDA-PDMA 795K was around130 nm. TEM images of binary particles gave a dense core surrounded witha light shell; due to the polymeric nature of the both the components,it was difficult ascertain which component constituted the shell(micrographs not shown).

Moreover, the process of self-assembly of the PDA-PDMA binary particleson the surface was studied using AFM force measurements and XPSanalysis. The composition of binary particles obtained by mixing 1:5dopamine and PDMA was similar to the original composition. However, thedeposition of PDA-PDMA particles changed the composition on surfacecoating. For instance the surface composition of the binary coatinganalyzed by XPS analysis gave a closer composition to PDMA than PDA-PDMAinitial composition suggesting the possibility of rearrangement ofpolymer chains upon particle deposition on the surface (FIG. 2A).

The surface structure of the binary coating was probed using AFM forcemeasurements (see FIG. 5B and 5E). AFM approach curves on binary coatingshowed typical profile for steric repulsion exerted by the polymergrafts on surface. Equilibrium thickness increased with increase in themolecular weight of the PDMA chains. Retraction curve on binary coatinggave characteristic profile for loop-like assembly of the PDMA chains onthe surface and the extension length increased with increase inmolecular weight of PDMA.

Based on these observations, a mechanism was proposed for the formationof a stable binary coating (FIGURE 5C) which influences theself-assembly of PDA polymerization. The mechanism involves series ofprocesses including (1) formation of uniform particles composed ofhydrophilic polymer and PDA through possible hydrogen bonding andhydrophobic-hydrophobic interactions, (2) deposition of particles on thesurface which influences the structure and thickness of the coatinglayer, (3) rearrangement of deposited PDA-PDMA particles on the surfaceby the rearrangement of polymer chains on the surface to from a PDMAenriched surface and (4) the formation of stable cross-linked binarycoating on the surface anchored by PDA on the surface and PDMApreferentially enriched on the surface. Compare to proposed mechanismsfor 43K, 213K and 795K PDMA (FIG. 9B) and for PEO and HPG (FIG. 9C).

Example 5: Adaptation of the Technology for Catheter Modification

Given the ability of the PDMA coating to prevent surface bacterialadhesion and biofilm formation, the surface-coating method was adaptedto prevent bacteria adhesion and subsequent biofilm formation on urinarycatheters. Biofilm formation on the urinary catheter increases the riskof sepsis in patients with indwelling catheters. Uncoated (pristine) andcoated (modified) catheters were exposed to 1×10⁶ cells/ml of S. aureusin LB medium for 6 h. Determination of the number of bacteria adhere onthe surface of PDMA coated samples showed a 86.3% to 96.1% reductioncompared to unmodified catheters (FIG. 6 ). Each group contains oneuncoated and one coated catheter, whereby 4 uncoated and 4 coatedcatheters for in vitro experiment were used.

In vivo experiments were also conducted, wherein coated and uncoatedcatheters (substrates) were produced for testing in a mouse model ofCatheter-associated urinary tract infection (CAUTI), to compare adherentbacteria and biofilm formation on the catheter surface when challengedwith 10⁸ CFU/mL S. aureus bacteria over 7 days. Catheters were placed ina buffer solution containing dopamine and ultra-high molecular weighthydrophilic synthetic polymers (PDMA-795K (10 mg/ml)). Bacterialadhesion in vivo of the anti-biofilm coated catheters was tested using amouse model of CAUTI, dramatically reducing (99.7%) adherent bacteriaand biofilm formation on the catheter surface compared to uncoatedcatheters when challenged with 10⁸ CFU/mL bacteria over 7 days (FIG. 6B)and also surprisingly showed a reduction of bacterial growth within theurine (FIG. 6C).

Example 6: Studies to Distinguish Low Molecular Weight and HighMolecular Weight PDA/PDMA Coatings

Synthesis of Coating:

Seven PDMA/PDA coatings were prepared with PDMA 43K (coatings 2 and 3),213 K (coatings 4 and 5) and 795K (coatings 6 and 7). The synthesisprocess is similar to previous experiments, however, some differencesare in terms of the ratio between PDMA and PDA used. The ratio ofPDMA/PDA is changed from 5:1 to 15:1 (wt/wt) to understand whether thecomposition change in the initial coating solution was influencing thephysico-chemical properties and biofilm formation.

TABLE 4 Experimental details and characteristics of PDA/PDMA coatingsPDMA Sample (Mn) & Ratio of ^(#)Thickness ^($)Thickness ^(@)Particle IDConc. Dopamine PDMA/PDA (Si) (Ti) Size Coating 1 2 mg/ml 33.2 nm 22.4 nm3000 nm  Coating 2 43K; 2 mg/ml  5:1 60.8 nm 57.9 nm 744 nm 10 mg/mlCoating 3 43K; 2 mg/ml 15:1 20.4 nm 16.6 nm 335 nm 30 mg/ml Coating 4213K, 2 mg/ml  5:1 19.1 nm 17.1 nm 341 nm 10 mg/ml Coating 5 213K, 2mg/ml 15:1 13.5 nm 15.8 nm 387 nm 30 mg/ml Coating 6 795K, 2 mg/ml  5:118.4 nm 15.5 nm 418 nm 10 mg/ml Coating 7 795K, 2 mg/ml 15:1 20.9 nm14.2 nm 511 nm 30 mg/ml ^(#)thickness of the coating is measured byellipsometry analysis on silicon wafer ^($)thickness of the coating ismeasured by ellipsometry analysis on Ti surface. ^(@)particle size(hydrodynamic size) is measured by dynamic light scattering.

Scanning electron microscopy (SEM) analysis was performed to determinethe morphology of the coatings prepared at different conditions. Thecoatings were scanned under both dry and wet conditions (aqueous).

Morphology of the coating depends on the molecular weight of the PDMA.Only high MW PDMA gave uniform coating. Even at higher ratio of low MWPDMA (15:1) uniform morphology was not observed. Uniform coating isneeded to generate low fouling surfaces (micrographs not shown).

Similarly, surface roughness was evaluated by AFM morphology analysis.Usually, a smooth surface gives better antifouling performance. Onlyhigh molecular weight PDMA along with PDA generated smooth surfacespossibly due to the differences in aggregation of PDA in presence ofPDMA. Unlike low MW PDMA (43K), High MW PDMA (213K and 795K) stabilizedthe particles which generated smooth deposition process (micrographs notshown). Micrographs taken at the same resolution show considerablesurface irregularities for PDA alone and PDA/PDMA-43K coated substrates,while PDA/PDMA-213K and PDA/PDMA-795K coated substrates showed almostcompletely uniform smooth surfaces at the same resolution.

Surface Chemistry by XPS Analysis (Substrate: Si)

Surface compositions of the different coatings set out in TABLE 4 werecompared. The nitrogen content increased with increasing polymer MW aswell as composition suggesting that more PDMA is accumulated on thesurface. Nitrogen content >10 At % (N/C ratio is >0.150) is onlyachieved for high MW PDMA based coating. The data suggests that there isan enrichment of high MW polymer on the surface compared to the low MWpolymer which produced the best anti-fouling performance.

TABLE 5 Comparison of chemical compositions of various depositedcoatings on silicon wafers based on X-ray Photoelectron Spectroscopy(XPS) Analysis. Sample C N O Si N/C Coating 1 59.28 6.38 30.96 3.380.108 Coating 2 71.40 8.10 20.20 0.30 0.113 Coating 3 71.43 9.34 23.621.83 0.132 Coating 4 69.02 9.55 21.12 0.31 0.138 Coating 5 55.42 8.3223.84 12.42 0.150 Coating 6 71.67 10.67 17.21 0.45 0.150 Coating 7 70.5411.78 17.13 0.55 0.167 Coating 5: Low N content is due to the thinnerlayer formed (see section 1).

AFM Force Curve Analysis

AFM force curve analysis was performed on different coatings and thedata are summarized below. Coatings prepared on Si wafer are used forthe analysis under aqueous conditions. The goal of the experiment was todetermine whether increasing the concentration of PDMA in the coatingcould alter the short range hydrophobic attractive forces and forcecurves.

FIGS. 9D, 9E and 9F show AFM force measurements of PDA/PDMA (43K, 213Kand 795K, respectively) coatings containing PDA/PDMA at 1:15 ratio(details given in TABLE 4), wherein the high MW PDMA coating hasdistinct force profile (approach and retract compared to low MW PDMAcoating). 795K shows almost no difference in the approach and retractionforces, but 213K and 43K show marked differences, which increase as themolecular weight decreases. The AFM force curves and analyses (FIGS.10A-D) clearly confirm that the structure of the coating prepared by lowMW and high MW PDMA is different. Hydrophobic interactions between theAFM tip and the coating illustrate that only high MW PDMA are able toprevent short range interactions. In addition, the shape of force curvesare different for low MW and high MW polymer coatings, which suggeststhat the organization of PDMA on the surface of coating is different. Inthe case of low MW PDMA/PDA coating, increase in the ratio of PDMA/PDAis not sufficient to prevent the hydrophobic short range interactions.High MW PDMA/PDA coating effectively reduces such interactions. Thisconfirms that difference the physical properties of the coating are dueto the MW of the PDMA and not due to the concentration. Only high MWpolymer is able to provide an optimal structure which significantlyreduces short range hydrophobic forces. The reduction in hydrophobicinteraction is correlated well with the early stage biofilm adhesion.

The Influence of MW and Composition of PDMA in the PDMA/PDA Coating onEarly Stage of Biofilm Formation.

Coatings prepared on titanium oxide surface were used for this analysisof S. aureus lux strain on biofilm formation after 24 h. Initialbacterial concentration was 106 CFU/mL in LB media. After 24 h ofincubation, CFU counts and fluorescent images are taken (micrographs notshown). Images and CFU data are analyzed using the following criteria.CFU/Image=0 equal to Adhesion Score=0; CFU/Image=1-10 equal to AdhesionScore=1; CFU/Image=10-10 equal to Adhesion Score=2; CFU/Image=100-1000equal to Adhesion Score=3; CFU/Image>1000 equal to Adhesion Score=4.

Coating 1 had an average Score of 3.25 (Adhered Bacteria/Image around500-1000). Coating 2 had an average Score of 3.00 (AdheredBacteria/Image around 500-1000). Coating 3 had an average Score of 2.75(Adhered Bacteria/Image around 500). Coating 4 had an average Score of2.5 (Adhered Bacteria/Image around 200). Coating 5 had an average Scoreof 1.75 (Adhered Bacteria/Image=44). Coating 6 had an average Score of1.25 (Adhered Bacteria/Image=13). Coating 7 had an average Score of 1.25(Adhered Bacteria/Image=22)

There was a reduction in bacterial adhesion with PDMA/PDA coating incomparison to control surface. There was reduced bacterial adhesion asMW of the coating increased. However, irrespective of the composition ofthe low MW PDMA used, the coating prepared from low MW PDMA (coatings 2& 3) were not as effective at resisting bacterial adhesion. High MW PDMAcoating effectively prevented bacterial adhesion.

Example 7: Comparison of Alternative Polymeric Binders for Use With HighMolecular Weight PDMA Coatings

Catechol (2 mg/ml) and polydimethylacrylamde (795K) (PDMA-795K (10mg/ml) were mixed together in aqueous buffer and coating was applied viaa simple dip coating process for 24 h at room temperature withoutstirring. 10 mM Tris buffer (pH=8.5) was used when DA or NE (see FIG. 11) was used for coating precursor. 10 mM Tris buffer with 0.6M NaCl(Ph=7.5) was used when TA or PG (see FIG. 11 ) was used for coatingprecursor. Titanium surface (Ti) was used as the substrate for coating.

TABLE 6 Characterization of the coatings generated by differentcatechols. PDMA ^($)Particle ^(&)Thick- Sample (mg/mL) Catechol Sizeness STDEV Ti-1 0 DA 3264.1 nm 18.8 nm 1.1 nm Ti-2 10 DA 370.7 nm 16.7nm 3.7 nm Ti-3 0 NE 617.8 nm 36.3 nm 1.3 nm Ti-4 10 NE 334.9 nm 13.7 nm1.6 nm Ti-5 0 TA 1652.9 nm 25.3 nm 1.5 nm Ti-6 10 TA 153.2 nm 16.2 nm3.3 nm Ti-7 0 PG 4121.2 nm 7.0 nm 0.3 nm Ti-8 10 PG 270.1 nm 4.1 nm 0.1nm ^($)particle size of PDMA (795K)/Catechol binary complex measured bydynamic light scattering. ^(&)thickness of the coating on Ti-surfacemeasured by elliposmetry measurements.

Selected polymeric binders were used to generate uniform binary coatingon Ti-surface. Fluorescence microscopy images of S. aureus adhesion onuncoated TiO₂; PDA/PDMA-795K coated TiO₂; PNE/PDMA-795K coated TiO₂;PTA/PDMA-795K coated TiO₂; PPG/PDMA-795K coated TiO₂ were compared after24 h incubation in LB medium with an initial concentration at 10⁶cells/ml. All the coatings were effective in preventing short-termbiofilm formation by S. aureus (data not shown). The fluorescence levelon the coated surface after bacterial adhesion was similar to thebackground.

PDA/PDMA (795K) coating of a Ti surface was placed in S. aureussuspension for 3 and 7 days to determin the prevention of long-termbiofilm formation. The biofilm formation was investigated using confocalmicroscopy after live-dead staining. Confocal fluorescence microscopyimages of S. aureus adhesion on uncoated TiO₂; were compared withPDA/PDMA-795K coated TiO₂ after 72 h incubation in TSB medium with aninitial concentration at 5×10⁴ cells/ml. Medium was changed every 24hours with a fresh addition of bacteria.

The PDA/PDMA (795k) coating was highly effective in preventing biofilmin enriched media(data not shown). Similar data for 7-day biofilminhibition has also been observed (data not shown).

Although various embodiments of the invention are disclosed herein, manyadaptations and modifications may be made within the scope of theinvention in accordance with the common general knowledge of thoseskilled in this art. Such modifications include the substitution ofknown equivalents for any aspect of the invention in order to achievethe same result in substantially the same way. Numeric ranges areinclusive of the numbers defining the range. The word “comprising” isused herein as an open-ended term, substantially equivalent to thephrase “including, but not limited to”, and the word “comprises” has acorresponding meaning. As used herein, the singular forms “a”, “an” and“the” include plural referents unless the context clearly dictatesotherwise. Thus, for example, reference to “a thing” includes more thanone such thing. Citation of references herein is not an admission thatsuch references are prior art to an embodiment of the present invention.The invention includes all embodiments and variations substantially ashereinbefore described and with reference to the examples and drawings.

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1-45 (canceled)
 46. A composition, the composition comprising: (a) apolymeric binder, wherein the polymeric binder is selected from one ormore of: polymeric norepinephrine (PNE); polymeric pyrogallol (PPG); andpolymeric tannic acid (PTA); and (b) a hydrophilic polymer, wherein thehydrophilic polymer is selected from one or more of: poly(acrylamide)(PAM); poly(N,N-dimethyl acrylamide) (PDMA); poly(N-hydroxymethylacrylamide) (PHMA); poly(N-hydroxyethyl acrylamide) (PHA); poly{N-[tris(hydroxymethyl) methyl]acrylamide} (PTHMAM);poly(methacrylamide) (PMA); poly(N-(2-hydroxypropyl)methacrylamide)(PHPMA);poly(N-(3-(methacryloylamino)propyl)-N,N-dimethyl-N-(3-sulfopropyl)ammonium hydroxide) (PMPDSAH); and poly(2-methacryloyloxyethylphosphorylcholine) (PMPC); wherein the hydrophilic polymer is a highmolecular weight hydrophilic polymer having a molecular weight ≥100,000daltons and wherein the composition is suitable for application to asubstrate and forms a stable mixture when in solution prior to contactwith a substrate.
 47. The composition of claim 46, wherein thecomposition further comprises: (a) a buffer; (b) an aqueous solution;(c) a water soluble organic solvent; or (d) water.
 48. The compositionof claim 47, wherein: (a) the aqueous solution lacks a salt; (b) thebuffer has a pH of between 7 and 12; or (c) the buffer comprises a salt.49. The composition of claim 46, wherein the ratio of a polymeric binderto hydrophilic polymer in mg/ml_is: (a) between 100:1 and 1:100; (b)between 1:1 and 1:30; or (c) between 1:5 and 1:15.
 50. The compositionof claim 46, wherein the hydrophilic polymer has a number averagemolecular weight (M_(n)) of: (a) at least 100 kDa; (b) at least 200kDa.; or (c) at least 300 kDa.
 51. The composition of claim 46, whereinthe polymeric binder is: (a) selected from one or more of: PNE; and PTA;(b) PNE; (c) PTA; or (d) PPG.
 52. The composition of claim 46, whereinthe hydrophilic polymer is: (a) selected from one or more of:poly(acrylamide) (PAM); poly(N,N-dimethyl acrylamide) (PDMA);poly(N-hydroxymethyl acrylamide) (PHMA); poly(N-hydroxyethyl acrylamide)(PHEA); poly {N-[tris(hydroxymethyl) methyl]acrylamide} (PTHMAM);poly(N-(2-hydroxypropyl)methacrylamide) (PHPMA);poly(N-(3-(methacryloylamino)propyI)-N,N-dimethyl-N-(3-sulfopropyl)ammonium hydroxide) (PMPDSAH); polv(carboxybetaine methacrylate)(PCBMA); and poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), (b)selected from one or more of: PAM; PDMA; PHMA; PHEA; and PHPMA; or (c)PDMA.
 53. A coated substrate, the coated substrate comprising: (a) asubstrate; (b) a polymeric binder, wherein the polymeric binder isselected from one or more of: polymeric norepinephrine (PNE); polymericpyrogallol (PPG); and polymeric tannic acid (PTA); and (c) a hydrophilicpolymer, wherein the hydrophilic polymer is selected from one or moreof: PAM, PDMA, PHMA, PHEA_(;) PTHMAM, PMA, PHPMA, PMPDSAH, PMPC, andDextran; wherein the hydrophilic polymer is a high molecular weighthydrophilic polymer having a molecular weight ≥100,000 daltons.
 54. Thecoated substrate of claim 53, wherein the substrate is a plastic, ametal, a ceramic, a carbon based material, a metal oxide, a hydrogel, abiological tissue, a wood or a cement.
 55. The coated substrate of claim53, wherein the substrate is: (a) selected from poly(propylene) (PP);poly(urethane) (PU); poly(ethylene) (PE); unplasticized polyvinylchloride (uPVC); plasticized polyvinyl chloride (pPVC); poly(imide)(PI); ethylene vinyl acetate (EVA); poly(tetrafluoroethylene) (PTFE);titanium dioxide (TiO₂), and silicon dioxide (SiO₂); (b) selected fromPP, PU, PE, uPVC, pPVC, PI, EVA, and PTFE; or (c) is TiO₂ or SiO₂. 56.The coated substrate of claim 53, wherein the substrate forms part of anapparatus,
 57. The coated substrate of claim 56, wherein the apparatusis selected from: a urinary device; a dental fixture; an artificialjoint; a vascular device; a storage device; a microfluidic device; afiltration membrane; a feed tube; or a diagnostic device.
 58. The coatedsubstrate of claim
 57. wherein: (a) the vascular device is selected froma catheter, a lead, and a stent; (b) the urinary device is selected froma urine storage device, catheter, and a stent; or (c) the filtrationmembrane is selected from a blood filtration membrane, a waterpurification membrane, and an air purification membrane.
 59. A method ofcoating a substrate, wherein the substrate is immersed in a solutioncomprising the composition of claim 46 or the substrate is sprayed witha solution comprising the composition of claim
 46. 60. The method ofclaim 59, wherein the method further comprises one or more of thefollowing: (a) drying the substrate; (b) applying a further coat of thesolution following the drying of the substrate; (c) a second drying ofthe substrate; (d) one or more repetitions of the applying a furthercoat of the solution followed by one or more subsequent drying steps;(e) mechanical agitation following immersion in the solution; or (f)application of a primer, prior to immersion in or spraying of asolution.
 61. The method of claim 60, wherein the drying is in flow ofargon gas or a flow of nitrogen gas.
 62. The composition of claim 46,wherein the composition is for use as an anti-fouling agent or for useas an anti-adhesion agent.
 63. The method of claim 59, wherein thecoated substrate reduces biofouling, reduces adhesion or reducesthrombus formation.